Protective starting device for internal combustion engines



1969 J. BJORKNAS 3,456,637

PROTECTIVE STARTING DEVICE FOR INTERNAL COMBUSTION ENGINES 2 Sheets-Sheet l Filed Aug. 21, 1967 mvzmon JOHN BJORKNAS i? 1969 J. BJORKNAS 3,456,637

PROTECTIVE STARTI NG DEVICE FOR INTERNAL COMBUSTION ENGINES Filed Aug. 21, 19 67 2 Sheets-Sheet 2' ATTOR NEYS 3,456,637 PROTECTIVE STARTING DEVICE FOR INTERNAL COMBUSTION ENGINES John Bjorkuas, 6576 Sussex Ave., Burnaby, British Columbia, Canada Filed Aug. 21, 1967, Ser. No. 661,850 Int. Cl. F02d 33/00 US. Cl. 123-140 9 Claims ABSTRACT OF THE DISCLOSURE A protective starting device for governor equipped internal combustion engines having a fluid operated piston movably responsive to a supply of engine developed pressurized fluid to control the operation of the fuel admission controls to prevent excess fuel being delivered to the engine during engine speed build up.

BACKGROUND OF THE INVENTION The present invention relates to a protective starting device for speed responsive governor controlled internal combustion engine limiting the amount of fuel supplied to the engine during the starting period required to start the engine, or to lessen that called for by the governor during the starting period.

It would be appreciated that governor of this type of engine will, during the starting period call for full fuel supply of the engine to bring the engine up to the predetermined operating speed or at least will call for a full supply considerably in excess of that required for startmg.

This can cause excessive ignition pressure during the first few cycles of the engine, excessive smouldering and may cause the engine to overshoot its predetermined operating speed.

These governor controlled engines are commonly used in driving electricity generators where it is critical the operating speed be adhered to. In such applications it is usual for there to be provision for shutting down the engine automatically should it exceed, by predetermined amount, the operating speed. This can mean that the engine could be shut down during the overshoot produced in the starting period and as a delay is commonly made before the engine is put on load, this shutting down during that period is very undesirable.

Further, with the overshoot, the period during which the engine settles down the operating speed can be considerable and if the engine is not put on load until that period has elapsed, serious problems can arise if the engine is being used as a standby engine where there is an appreciable lag between the standby engine being called for and it becoming available.

It is appreciated that protective starting devices have heretofor been designed for limiting the admission of fuel in excess of that required to start the engine. However, such devices have normally required auxiliary power sources for the operation. Furthermore, such devices have been relatively expensive to produce and install.

SUMMARY OF THE INVENTION The present invention provides a very simple protective starting device which is inexpensive to manufacture and install and which utilizes, as its power source, any suitable pressurized fluid supply, the pressures in which are developed by the engine itself. The present invention, therefore, eliminates the need for auxiliary power sources as above mentioned. I

The present protective starting device for constant speed internal combustion engines having an engine pressurized fluid supply and a speed responsive governor which has '1 tilted tates Patent 3,456,637 Patented July 22, 1969 ice fuel admission control means for regulating the supply of fuel to the engine comprises cylinder means, piston means in the cylinder means operatively associated with the control means, said piston means being movable between a limiting position for limiting the control means to admitting that amount of fuel required to start the engine and a non-limiting position in which the governor alone is permitted to control the control means so as to maintain the engine at a constant predetermined operating speed, resilient means urging the piston means to a normal limiting position, pressure conduit means connecting the cylinder means to the fluid supply for moving said piston means to said non-limiting position and fluid admission regulating means for regulating the flow of fluid into the cylinder means so as to provide controlled movement of the piston means during build up of engine speed.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a central sectional view of one embodiment of the invention illustrated in a position prior to start-up of the engine,

FIGURE 2 is a central sectional view of the embodiment of FIGURE 1 illustrating the latter in position after the engine has reached its operating speed.

FIGURE 3 is a central sectional view of another embodiment of the invention showing the latter in two operating positions and FIGURE 4 is a view similar to FIGURE 3 of said other embodiment illustrating the latter in a position after the engine has attained its predetermined operating speed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings and in particular to FIG- URES 1 and 2 thereof, there is illustrated one embodiment 10 of the fuel limiting device.

The device 10 includes a cylindrical casing 11 formed of upper 12 and lower 13 sections, said sections being fastened to each other as by bolts 14, so as to form an enclosed cylinder 16 having a vented upper end wall 17, a lower wall end 18 and a cylindrical wall 19. In the cylinder is a cup shaped piston 20 the diameter of which is smaller than the diameter of the cylinder so as to provide a loose fit therein.

This piston has a centrally apertured base 21 through which a piston rod 22 extends. This piston rod has an exterior flange 23 at one end which engages the base 21 of the piston and is partially threaded as at 24 to receive a nut 25 which is tightened down against the base 21. This piston rod slidably extends through a suitably sized hole 26 formed in the lower end wall 18, said end wall being I provided with an annular groove 27 for receiving an O- against the lower end 33 of the piston rod 22.

A pliable roll-type diaphragm 35, which may be formed of leather or other suitable material, is mounted over the piston rod 22 between the piston 20 and nut 25, and extends at its periphery between the upper and lower sections 12 and 13 of the casing 11, so as to permit unhindered movement of said piston.

Between the upper end wall 17 and the piston 20 is a coiled compression spring 37 which normally urges the piston rod to an extended or fuel limiting position as illustrated in FIGURE 1 of the drawings.

The device 10 is connected to a suitable source'of engine developed pressure fluid supply, preferably to the engine lubricating oil pump (not shown), of the engine to be governed. The casing 11 is therefore provided with an intake passage 38 ported at one end 39 into the cylinder 16 below the diaphragm and ported at its other end 40' into an internally threaded socket 41 into which a conduit 42 of suitable size is threaded and connected to said lubricating oil pump. A needle valve 43, threadly engaged in an access passage 44, extends into the intake passage 38 whereby the how of oil through the intake passage may be regulated.

An oil outlet passage 45 is also provided, ported at one end 46 into the cylinder below the diaphragm and at its other end 47 to the socket 41. This outlet passage also has an enlarged check valve chamber 48 in which a balltype check valve 49 is positioned being urged by a spring 50 against a seat 51. This check valve permits all the oil entering the cylinder to be directed through the intake passage but permits free and unrestricted flow of oil out of the cylinder. This allows the device to be quickly reset rather than allowing the piston 20 to be slowly returned to its initial position when the engine is shut down. It will be appreciated that if the check valve were not provided, the oil below piston 20 would only leave that space slowly under the influence of spring 37, past the needle valve, so that should the engine be shut down and quickly restarted, the limiting device would not be effective.

It is not intended that the use of the device shall be restricted to any one type of governor. However, in order to describe its use it is illustrated, in FIGURES 1 and 2, in association with a governor 52 having an operating rod 53 the movement of which is controlled by the speed responsive mechanism,not shown, with which the governor is equipped. This operating rod is operatively connected to a fuel admission control rod 54 via a beam 55 which is normally mounted for pivotal movement about a fixed pivotal point as at A so that movements of the operating rod 53 as controlled by the speed responsive mechanism of the governor will result in corresponding movements of the control rod 54 thereby adjusting the amount of fuel delivered to the engine. The operating rod 53 of governor 52, is arranged for up and down movements which are transmitted by the beam 55 to up and down movement of the control rod 54.,

Governor 52 is arranged so that when the engine, which the governor controls, is stationary, the operating rod 53 is positioned at a lower limit thereby positioning the control rod 54 at its upper limit wherein the fuel admission 'means to the engine are fully open. With this arrangement, and without a fuel limiting device, when the engine is started an overabundance of fuel will be admitted resulting in high ignition pressures and, due to the excess amount of fuel initially delivered, the engine will usually overrun its predetermined constant or operating speed even though the operating rod 53 has moved to result in fuel limiting movement of the control rod 54.

In the use of the device 10 the beam 55 instead of being pivotally secured about a fixed pivotal point, is pivotally connected by suitable means to the lower end 56 of shaft 31, said shaft being adjusted so that with the engine in a stationary condition the control rod 54 is positioned so that the fuel admission means are not fully open but arranged to admit only sufficient fuel to start the engine. When the engine starts, lubricating oil will be conveyed into the cylinder 16 below the diaphragm 35. As oil pressure builds up with build-up of engine speed, the piston will gradually be moved upward in the cylinder against the spring 37 thereby moving the shaft 31 upwardly and permitting upward movement of the control rod 54 and consequently permitting an increase in the admission of fuel to the engine as called for by the governor to bring the'engine to its operating speed and maintain it at that speed. The movement of the piston is such that when the spring is fully compressed, (see FIGURE 2) the shaft will have moved upwardly a distance suffi cient to place the pivotal point of the beam in a position wherein the speed responsive movements of the operating rod 53 may be transmitted to the control rod 54 to maintain the engine at operating speed; The rate of movement of the piston from its initial limiting position may be regulated by adjustment of the needle valve so as to regulate the rate of increase of fuel admission to the engine thereby eliminating excessive ignition pressures and engine speed overrun as herein before mentioned.

The shaft 31 will remain in this latter position until the engine is stopped at which point, due to decrease in oil pressure, the check valve will open and permit the spring 37 to again return the piston and with it the shaft to its initial limiting position.

In certain types of engines it may be preferred to have the engine attain its fully operating speed under no load conditions and under the fuel limiting action of the device 10 before permitting the governor to assume full control of the admission fuel. A small amount of air or if preferred, an inert gas, is introduced below the diaphragm and by suitable adjustment of the shaft 31, the beam is positioned so that regardless of the initial demands of the governor, the upward limit of movement of the control rod 54 is sufficient only to permit the engine to receive enough fuel to permit relatively slow build up of engine speed to operating speed under no load conditions.

Upon engine start-up, upward movement of the piston will be delayed until the pressure of the gas or air trapped beneath the diaphragm has risen sufiiciently to overcome the pressure of the spring 37. The length of the delay may be adjusted by appropriate adjustments to the needle valve 43 so that the piston will not begin to move until the engine has attained its operating speed.

Device 10 may also be operatively connected to the governors speed control adjusting mechanism, herein accorded the numeral 57, by means of which the desired constant speed of the engine may be adjusted. The mechanism 57 normally utilizes an adjusting lever 58 which may be positioned between a slow engine speed and a fast engine speed as indicated by the letters S and F respectively on a calibrated dial 59. The shaft 31 is operatively connected to the lever 58 in a suitable manner to provide for movement of the lever 58 from its slow engine speed to a desired ultimate predetermined engine speed as the engine speed builds up from start. The needle valve 43 is adjusted so that the shaft 31 will move the lever 58 from a slow engine speed to the desired constant or operating speed over a predetermined time interval thereby eliminating speed overrun of the engine above said operating speed.

FIGURES 3 and 4 illustrate another embodiment 60 of the device.

Device 60 includes a casing 61 having a lower cylinder 62 and an upper cylinder 63 which is of smaller diameter than the lower cylinder and opens into the latter. The lower cylinder is formed of a lower section 64 having a centrally apertured base 65 and an upper section 66 bolted to said lower section, said upper section terminating in an annular upper end wall 67 the inner edge 68 of which defines the lower end of the upper cylinder 63. The upper cylinder 63 is also of two-part construction having a lower section 69 which extends upwardly from said upper end wall 67 to which an upper end section 70 is bolted said upper end section being closed at its upper end 71.

A tubular shaft or guide 73 extends through the apertured base 65, the latter being provided with an O-ring 74 seated in an internal annular groove 75 and sealably and slidably engaging said shaft 73. At the upper, or inner end 76 of the shaft 73 is secured an annular piston 78 in the same manner as piston 20 is fastened to piston rod 22 of the device 10. Fastened to said piston 78 is a pliable roll-type diaphragm 79, the latter being secured at its peripheral edge 80 between the upper and lower sections of said lower cylinder 62. A coil spring 82 ismounted between the piston 78 and end wall 67 urging the piston against the base 65.

An elongated piston rod 85 is slidably mounted in shaft 73 extending outwardly out of both ends of the latter and the annular piston 78. At the upper or inner end 86 of piston rod 85 is mounted a piston 87 which extends into the upper cylinder 63 said piston 87 being of smaller diameter than said upper cylinder 63 so as to be freely reciprocable therein. A pliable roll-type diaphragm 89 is located over the upper end 86 of the piston 87 and extends at its peripheral edge 90 between the upper and lower sections of the upper cylinder 63. Said piston 87 is also provided with a radially extending annular flange 91 and mounted over piston rod 85 and extending under compression between said annular flange 91 and the piston 78 is a compression spring 93 which normally urges said pistons apart.

At is lower end 95 piston rod 85 is provided with a downwardly opening internally threaded bore 96 which threadedly receives an externally threaded shaft 97, the latter being locked in position by a lock nut 98 threaded thereover and adapted to be tightened down against the lower end of said piston rod 85. Upward movement of piston rod 85 relative to rod 78 is adjustably limited by means of a lock nut 99 threadedly engaged with an exteriorly threaded lower end portion 100 of rod 85.

The lower cylinder 62 is provided with a vent hole 100 which extends through the casting above th diaphragm.

The lower cylinder 62 has an oil inlet passage 101, controlled by a needle valve 102. The oil is exhausted from the lower cylinder thereof to an exhaust passage 104 controlled by a spring-urged ball valve 105. Both inlet and exhaust passages 101 and 104 respectively, are connected via a suitable conduit 106 to the engine lubricating oil pump, not shown. The upper cylinder 63, above the diaphragm 89, is likewise connected via conduit 107 to either the oil pump as aforesaid or to another suitable source of engine pressurized fluid.

The flow of fluid into and out of the upper cylinder 63 is not restricted in any way.

Device 60 is primarily intended for use with a governorequipped engine which is operated under low temperature conditions and which requires that the engine initially be supplied with a considerable quantity of fuel in order to have it fire but once firing takes place requires a lesser amount of fuel to obtain "build-up of engine speed to the desired predetermined or operating speed.

In its use, device 60 may be employed with the same governor as device and accordingly the same numerology will be used for both governors. The device 60 is arranged with the shaft 97 pivotally connected to the beam 55 in the same manner as shaft 31, that is intermediately between the operating rod 53 and control rod 54. At stationary engine conditions the device 60, not being subject to oil pressure in either the upper or lower cylinders thereof, will assume a starting position as illustrated in FIGURE 3. In this position the shaft 97 is adjusted so that regardless of the position of the operating rod 53, the control rod 54 will admit suflicient fuel to obtain firing of the engine under cold conditions.

Upon firing of the engine and consequent pressurizing of the engine lubricating oil, the oil will immediately flow into the upper cylinder and push the piston 87 downwardly against the spring 93 to a limiting position as illustrated in dotted lines in FIGURE 3 so as to result in movement of the control rod 54 to a position in which the fuel admitted to the engine is suflicient to keep the latter running but the beam 55 will still be held under the action of the lower piston which operates in the manner of the embodiment of FIGURES 1 and 2 to limit the admission of fuel to the engine until such time as sufiicient engine oil has flowed past the valve 102 to raise the rod 85 to its non-limiting position at which the governor can call for and obtain, full fuel admission. This second limiting action is effected by the fluid flowing past the needle valve 102 and into the lower cylinder which causes the piston 78 to move upwardly against the spring 82 thereby moving at a controlled rate, the piston 87, and with it the beam 55, upwardly into a position illustrated in solid lines in FIGURE 4 of the drawings wherein the operating rod 53 is permitted to control the operation of the control rod 54 to permit full fuel flow when called upon to do so by the speed control mechanism of the governor.

Air or an inert gas may also be introduced beneath diaphragm 89 so as to delay movement of the piston in the same manner and for the same reasons the movement of piston 20 of device 10 is delayed.

I claim:

1. A protective starting device for a constant speed internal combustion engine having an engine pressurized hydraulic fluid supply and having a speed responsive governor, said governor having fuel admission control means for regulating the admission of fuel to the engine, said device comprising: cylinder means, piston means in the cylinder means operatively associated with the control means, said piston means being movable between a limiting position for limiting the control means to admitting the amount of fuel required to start the engine and a non-limiting position in which the governor is permitted to control the control means so as to maintain the engine at a constant predetermined operating speed, resilient means urging the piston means to a limiting position, pressure conduit means connecting the cylinder means to the fluid supply for moving said piston means to said non-limiting position against the action of the resilient means when the engine is started, and fluid admission regulating means for regulating the flow of fluid into the cylinder means so as to control the rate of movement of the piston means to said non-limiting position.

2. A protective starting device for a constant speed internal combustion engine having an engine pressurized hydraulic fluid supply and having a speed responsive governor, said governor having fuel admission control means for regulating the admission of fuel to the engine, said device comprising a cylinder closed at one end and vented to atmospheric pressure at the other end, a piston in the cylinder, a piston rod connected to the piston and slidably and sealably extending through the closed end of the cylinder and being operatively associated with the control means, said piston being movable between a limiting position for limiting the control means to admitting that amount of fuel required to start the engine and a non-limiting position in which the governor is permitted to operate the control means to maintain the engine at a constant predetermined operating speed, a compression spring between the other end of the cylinder and piston urging the latter to its limiting position, a pressure conduit connecting the fluid supply and cylinder for delivering pressurized fluid between the piston and closed end of the cylinder for moving the piston against the action of the spring to its non-limiting position, when the engine is started and fluid admission regulating means for regulating the flow of fluid into the cylinder so as to control the rate of movement of the piston to said nonlimiting position.

3. A device as claimed in claim 2 including a gas containing enclosure between the piston and the closed end of the cylinder for cushioning the action of the pressurized fluid so as to delay the movement of the piston towards its non-limiting position.

4. A device as claimed in claim 2 including a discharge passage bypassing the fluid admission regulating means and provided with a check valve for permitting rapid discharge of the fluid from the cylinder when the engine i stopped.

5. A protective starting device for a constant speed internal combustion engine having an engine pressurized hydraulic fluid supply and having a speed responsive governor, said governor having fuel admission control means for regulating the admission of fuel to the engine, said device comprising: first and second cylinders connected into and in coaxial relationship, said cylinders opening at their adjacent end into each other and being closed at their opposite ends, the first cylinder having a larger diameter than the second cylinder, an annular piston in the first cylinder, a tubular shaft connected to the annular piston and slidably and sealably extending through the closed end of the first cylinder, a piston in the second cylinder, 2. piston rod connected to the second cylinder and slidably extending through the annular piston and tubular shaft, said piston rod being operably connected to the fuel admission control means, first resilient means normally urging the first piston and tubular shaft to an extended position relative to the first cylinder, second resilient means extending under compression between the first and second pistonsfor urging the said second piston to an engine starting position in which the control means admits the fuel required to start the engine, a first pressure conduit connecting the second cylinder and fluid supply for moving the second piston against the action of the second resilient means to an initial limiting position in which the control means is permitted to admit a lesser amount of fuel than that required to start the engine but suflicient to maintain the engine running, a second pressure conduit connecting the first cylinder and fluid supply for moving the first piston and with it the second piston, against the action of the first resilient means and the pressure of the fluid in the second cylinder to a non-limiting position in which the control means is permitted to admit full fuel flow into the engine in response to demands by the governor, and fluid admission regulating means for regulating the flow of fluid into the first cylinder so as to control the rate of movement of the second piston to said non-limiting position.

6. A device as claimed in claim 5 including a gas containing enclosure trapped between the first piston and the closed end of the first cylinder so as to delay movement of the second piston to its non-limiting position.

7. A device as claimed in claim 5 in which the fuel admission regulating means comprises a needle valve extending into the second pressure conduit for limiting the flow of fluid therethrough, said needle valve being adjustable.

8. A device'as claimed in claim 5 including a discharge passage bypassing the fuel admission regulating means and provided with a check valve for permitting rapid discharge of the fluid from the cylinder when the engine is stopped. Y

9. A device as claimed in claim 5 including a roll-type diaphragm in each cylinder from each diaphragm being operably and sealably associated with its associated piston.

References Cited STATES PATENTS UNITED 2,589,788 3/1952 Fell 123-140XR 2,879,754 3/1959 Von Kienlin 123 3,204,623 9/1965 Isley et al. 123 140 3,204,624 9/1965 Rutenber et al. 123-179 3,311,101 3/1967 H1158 123 179 3,311,102 3/1967 Voigt r.123 179 LAURENCE M. GOODRIDGE, Primary Examiner l V U.S. c1. X.R. 

